Shengmin Sang, ssang@ncat.edu, North Carolina Agricultural and Technical State University, North Carolina Research Campus, Kannapolis, NC 28081, United States
Ginger, the rhizome of Zingiber officinale, has been utilized for thousands of years as a spice and crude drug. The major pharmacologically active components of ginger are gingerols and shogaols, which have both been implicated in chemoprevention over the past decade. Shogaols are the products of gingerols after thermal processing and are the primary constituents of dried ginger. Our group demonstrated that [6]-, [8]-, and [10]-shogaols exhibited significantly higher toxicity to HCT-116 human colon and H-1299 human lung cancer cells than [6]-, [8]-, and [10]-gingerols. We have also found that [6]-shogaol was more effective than [6]-gingerol in inhibiting 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced skin tumor promotion in mice. Our studies on the metabolism of [6]-shgaol indicated that it is extensively metabolized in cancer cells, in liver microsomes, and in vivo. Our results also found that most of the metabolites of [6]-shogaol remain bioactive and some of the metabolites even have greater activity than [6]-shogaol in cancer cells and in mice.